Switch and signal control system for railroads



Nov. 17, 1942.

I N. B. COLEY 2,302,006 SWITCH AND SIGNAL CONTROL SYSTEM FOR RAILROADS Filed April 10, 1940 5 Sheets-Sheet 1 To I 197 199: F H INVENTOR 1. I

Nov. 17, 1942. CQLEY 2,302,006

SWITCH AND SIGNAL CONTROL SYSTEM FOR RAILROAD-'5 Filed April 10, 1940 5 She'ets-Sheet 2 Fl G .1.B.

. I BY 724d AZ 66 ATTORNEY Nov. 17, 1942.

, N. B. COLEY SWITCH AND SIGNAL CONTROL SYSTEM FOR RAILROADS Filed April 10, 1940 5 Sheets-Sheet 3 NOV. 17, 1942. B CQ] EY 2,302,006

SWITCH AND SIGNAL CONTROL SYSTEM FOR RAILROADS Filed April 10,1940 *5 Sheets-Sheet 4 AND AXB D Qzsm ' 212 INVENTOR BY ATTORNEY O 1942- N. B..COLEY 2,302,006 I SWITCH AND SIGNAL CONTROL SYSTEM FOR RAILROADS Filed April 10, 1940 5 Sheets-Sheetfi FIG-.35. V r

Patented Nov. 17, 1942 SWITCH AND SIGNAL CONTROL SYSTEM FOR RAILROADS Nelson B. Coley, Rochester, N. Y., assignor to General Railway Signal Company, Rochester, N. Y.

Application April 10, 1940, Serial No. 328,908 g 19 Claims. (01. 246134) This invention relates to'switch and signal I control systems for railroads, and it more particularly pertains to such systems of the entrance-exit type.

In an entrance-exit type of switch and signal control system, a control machine at a control office has a control panel upon which a miniature track diagram of the track layout is located and upon such diagram is disposed buttons for the entrance and exit ends of each of the routes extending through the track layout betweenroute ends which are usually defined by the location of wayside signals. The establishment of each route through the track layout is accomplished'in response to the designation by an operator ofthe respective entrance and exit ends of that route by the actuation of the control buttonson the control panel for the respective entrance and exit points.

It is further provided in some entrance-exit systems that an operator, in designating a route to be established extending past several signals, be required to actuate only the buttons for the extreme ends of that route, thus providing through route or end-to-end control past the intermediate signals included between the extreme entrance and exit ends of that route. In such systems, it is also provided that a through route can be set up by designating the entrance and exit ends of each track portion or interlocked group in such through route, as well as by through route control. It is to be understood that an interlocked group comprises one or more track switches interconnecting different stretches of track for setting up routes over such stretches of track between signals for the ends of the routes.

One object of the present invention is to provide in accordance with the operating requirements of railway practice, that manipulation to establish through routes is effective only for routes governed by one class of signals, such, for example. as by high speed signals, and it is not effective for the establishment of routes governed by another class of signals, such for example, as I.

low speed signals.

More specifically, in setting up a through route extending through several interlocked groups, the

establishment of a route in each of those interlocked groups and the clearing of the high speed signal for the entrance to each of such groups can be effected only by manipulation of the control buttons for the extreme ends of such through route in a manner characteristic of high speed signal control. The manipulation of the same buttons in a manner characteristic of low speed signal control fails to establish any route and fails to clear any signals. However, the manipulation of the control buttons for the entrance and exit ends of any route Within a single interlocked group in a manner characteristic of the low speed signal control, efiects the establishment of that route and the clearing of the proper low speed entering signal. In other words, the designation of an entrance point for the establishment of a route renders endtoend control eifective or ineifective for that route, dependent upon the distinctive character of the manipulation for the entrance end of such route. I

This invention is to be considered as an improvement over the entrance-exit system disclosed in the prior patent of S. N. Wight, Patent No. 2,265,258, dated December 9, 1941, and no claim is made herein to anything disclosed in that application. In that application a circuit network conveniently called an initiating network is provided for each direction of traffic for energizing selecting relays for the trailed track switches and for conditioning exit relays for each of the exit points, that is, the designation of an entrance point energizes the selecting relays for certain switches trailed in the various routes originating at that entrance point dependent upon the availability for use of such routes, and also conditions for energization the exit relays for the ends of such available routes ready for energization upon the actuation of its associated control button. Each of the initiating circuit networks includes circuit selections in branches or circuit portions to conform to the track layout for which the system is provided so that energy is fed through each branch of the circuit network corresponding to a route, when an entrance point is designated, only so far as the portions of track corresponding to such branches are available for use. Thus, where through route control is provided, the designation of an entrance point causes energy to feed through the branches of the initiating network corresponding to the available routes of the track layout, even when those routes extend through several interlocked groups, t

such energization of the initiating network being indiscriminate of the particular kind or class of signal at the entrance point which is designated by an operator.

Another object of the present invention is to employ polarized initiating circuits so that energy of one polarity will flow through each of the various branches of the initiating circuit network responsive to the designation of an entrance point only so far as such branches correspond to a route or routes included within that single interlocked group with which such entrance point is associated, if the designation of that entrance point has been characterized for the clearing of a low speed or dwarf signal. If, however, the operator has distinctively actuated the button for that entrance point in a manner to clear a high speed signal, energy of the opposite polarity will flow through each of the various branches of the initiating network corresponding with available routes extending from that entrance point, even if such routes extend through several interlocked groups. ating networks in response to the designation of an entrance point, whether for routes within the same interlocked group or for through routes originating at that entrance point, prepares for energization the exit relays for the exit ends of such of those routes as are then available for use, so that the actuation of the control button associated With any such exit relay to designate an exit end of one of such available routes causes that exit relay to be picked up and that particular route to be established as well as the clearing of its governing signal.

Thus, the system of the present invention is so organized that the distinctive actuation of a control button to designate an entrance point determines whether a control button can be effective, when subsequently actuated, to designate an exit point within the same interlocked group to establish a route governed by a low speed signal, or Whether a control button can be effective, when subsequently actuated, to designate the exit end of some through route governed by high speed signals.

According to the above description, it will be understood that the embodiment of the present invention provides means for limiting the use of low speed signals to routes within their associated interlocked group. Also, it will be seen that the high speed signals may also govern trafiic over certain of the same routes that have low speed signals for governing traiiic thereover, with the system so organized that the character of the distinctive actuation of a control button to designate an entrance signal location acts to determine whether the low speed or the high speed signal shall be used for the particular route to be set up. Although such an arrangement is highly desirable, it may happen that certain entrance points will have routes originating thereat which should have trafiic governed thereover only by low speed signals. In other words, there may be certain routes within a single interlocked group of such a nature that no high speed signalshould be cleared at any time to allow traffic to pass over such routes. Therefore, another object of the present invention is to provide means for limiting the use of high speed signals to only those routes which may have high speed traiii'c, and; in accordance with the present invention this is accomplished through the medium of the polarized initiating networks above mentioned. When the present invention is This energy which flows over the initiapplied to any particular installation, it is: then determined which routes shall have only low speed signals governing trafiic thereover so that whether a low speed signal or a high speed shall be provided for such routes is then no longer under the control of the operator of such a system, although the manual manipulation for the entrance ends of such routes may be required to be of the same distinctive character as provided for the entrance signal locations for those routes where the operator may choose as to whether a low speed or a high speed signal shall be cleared.

Another object of the present invention is to provide means for embodying the principles of the invention in such a manner that such means can be readily adapted for use in accordance with various practices of foreign railways. Such foreign practices differ in many respects from the operating practices generally known in this country because of the radically different operati'ng rules under which such foreign railroads are required to function. One form of foreign practice is to provide separate signals for high and low speed train movements which are conveniently termed running and shunting signals, respectively, which shunt signals are used primarily for switching operations; while the running signals are used for train movements continuing through an interlocking plant, and when a train is proceeding on such running signals the engineer ignores the condition of the shunt signals. In other Words, the establishment of a route governed by a running signal is completed past shunt signals, without clearing those shunt signals which may be intermediate to the cleared running signal and the next runing signal for governing traffic in the same direction, or to an arbitrary point as the exit end of the route. The control of the shunt signals diifers from practice in this country in that, when several shunt signals are to be cleared for traffic approaching a particular point in the track layout, it is required that any given one of such shunt signals can be cleared only when the next shunt signal in advance is cleared. It is further provided that the setting up of routes governed by shunt signals cannot be effected by end-to-end or through route control.

The present invention is therefore particularly adaptable to these differing practices by the use of control buttons which may be distinctly actuated. in combination with polarized initiating circuits for causing the different entrance-exit manipulations of a control machine to be oo-extensive with the extent of trackway over which the signals of the diiferent classes may govern traffic.

It is believed that other objects, purposes and characteristic features of the present invention will be more readily understood from reference to the accompanying drawings and as they are pointed out hereinafter in the description of the present invention.

In describing the invention in detail, reference will be made to the accompanying drawings in which corresponding parts are designated by corresponding reference characters as they appear throughout the several drawings, in which similar letter reference characters are used to designate parts of the same general nature, such parts being usually made distinctive by reason of preceding numerals or by preceding letter reference characters representative of the signal locations, and in which:

Figs. 1A and 13, when placed side by side, illustrate the track diagram on a section of the control panel of a control machine for the track layout for which the present embodiment of the invention is provided, together with circuit means for establishing each desired route according to railroad practice in this country through the track layout and for clearing the signal governing entrance thereto;

Fig. 2 illustrates the track layout for which this embodiment of the present invention is provided, together with various typical control circuits relative to the safe operation of the track switches and the governing of the signals;

Figs. 3A and 33, when placed side by side, illustrate a portion of the control panel of a control machine having a miniature track diagram corresponding to the track layout illustrated in Fig. 2, together with circuit means for the establishment of routes through the track layout and the clearing of signals governing entrance to such routes in accordance with the requirements of foreign railway practice;

Fig. 4 illustrates how the route locking is modifled from the form shown in Fig. 2 in order to conform to foreign railway practice; and Fig. 5 illustrates diagrammatically a typical signal mechanism used in the embodiment of the present invention.

Rather than show the specific construction and arrangement of parts that would be employed in practice, the drawings have been arranged to disclose as clearly as possible the mode of operation of the system and the principles involved. Thus, the various relays and their contacts are shown in a conventional manner, corresponding relays and corresponding contacts being readily identified throughout the drawings by like reference characters. Certain circuit details well known to those familiar with the art are merely indicated by dotted lines, and symbols are used to indicate connections to the terminals of batteries or other sources of electric current instead of showing all of the wiring connections to such terminals.

The symbols and are employed to indicate the positive and negative terminals respectively of suitable batteries or other sources of direct current, and the circuits with which those symbols are used always have current flowing in the same direction. The symbols (B+) and (B) are used to indicate connections to the opposite terminals of a suitable battery, or other direct current source which has a central or intermediate tap designated (CN) and the circuits with which those symbols are used may have current flowing in one direction or the other dependent upon the particular terminal used in combination with the intermediate tap (CN).

Reference is made from time to time in the description to functions common to all parts of a similar kind or class by use of the letter ref erence characters common to such parts without their distinctive preceding numerals or letters representative of signal locations for the purpose of facilitating in the description of the present invention, such a reference being understood to apply to each of the parts in that particular class.

Track Zayout.-With reference to Fig. 2 of the accompanying drawings, the track layout for this embodiment of the present invention consists of a main track having two other tracks connected thereto by single track switches 2 and 3 respectively. It is to be understood that the simple track layout chosen for the disclosure of the present invention is chosen primarily for the purpose of simplifying the disclosure as to the mode of operation and the principles involved, rather than to limit the scope of the present invention, inasmuch as the present invention embodies principles which make it readily applicable to the many complex track layouts encountered in practice. In fact, it is contemplated that the usual embodiment of the invention in actual practice will include crossovers as well as single switches interconnecting several different tracks providing all kinds of routes, such as alternative and run-around routes, through-routes, and the like.

The operation of each of the track switches is effected by a power operated switch machine SM which can be, for example, of the type shown in the patent to W. K. Howe, Patent No. 1,466,903, dated September 4, 1923. It is to be understood that suitable over-load protection is provided for the switch machine motors such, for example, as is shown in the patent to W. H. Hoppe et al., Patent No. 1,877,876, dated September 20, 1932.

A normally energized polar neutral switch repeater relay WP is provided in the usual manner for repeating the position of each track switch in correspondence with the position of its switch machine SM. For example, the track switch 3 has associated therewith a switch repeater relay 3WP which is energized to operate its polar contacts to a right-hand position when that track switch is locked normal in correspondence with the position of its switch machine 3SM, and such WP relay is energized with its polar contacts operated to a left-hand position when the track switch 3 is locked in a reverse position in correspondence with the position of its switch machine 3SM. The relay 3WP is deenergized whenever the track switch 3 and/or the switch machine SM are unlocked or out of correspondence. Such control of the relay W? for each of the track switches is provided by means of a point detector contact mechanism such, for example, as the mechanism shown in the patent to C. S. Bushnell, Patent No. 1,517,236 dated November 25, 1924.

Signals are provided for governing traffic through the track layout in both directions, signals A, B1, B2, Cl, C2, F and G being provided for governing east-bound traffic to the right, and signals D and E being provided for governin west-bound traffic to the left (see F g. 2). Each of the signals is assumed to be of the searchlight type of the general character shown. for example, in the patent to O. S. Field. 1,835,150. dated December 8, 1931; but it is to be understood that other types of signals can as well be used with the system provided by the present invention, such, for example, as semaphore sic-- nals, and color light signals having individual color lamp units.

A typical mechanism of one of these searchlight signals as employed in the embodiment of this invention has been shown in Fig. 5. This mechanism comprises an optical unit and an electro-magnetic structure for operating the color roundels to their different positions for changing the color indications of the signal. as well as including certain contacts which are operated in accordance with the position of the color roundels. With reference to Fig. 5, a lamp I86 is illustrated as being steadily energized for illuminating the signal, but it is to be understood that approach lighting may be employed if desired. This lamp I supplies light through the lens or optical arrangement of the signal. which light must pass through the particular colored roundel then in the center or active position. The roundels indicated in the drawing are green. red and yellow indicated by the letters G, R and Y, respectively, which roundels are on the movable member l8l assuming its biased to normal position with the red roundel R in front of the lamp I80. When the coil I82 of the mechanism is energized with positive potential on the upper terminal, the electro-magnetic driving structure causes the movable member [8! to rotate clockwise so that the green roundel G is in the active position; and similarly when the upper terminal of the winding I82 is energized with negative potential the movable member ISI is caused to rotate counter clockwise so as to place the yellow roundel Y in the active position.

When the movable member I8! is actuated to place the green roundel G in the active position, the contact I83 is moved to the right, and when the movable member I8! is actuated so as to place the yellow roundel Y in the active position, the contact I84 is moved to the left position. But when the winding I82 is deenergized and the movable member |8l assumes its normal position with the red roundel R in the active position and the contacts I83 and E84 assume their biased to normal positions.

When the movable member [3! is actuated to either energized position, it is apparent that the relay GYP is energized by obvious circuits, but when the member IN is in its normal position, the relay GYP is always deenergized. In other words, the relay GYP may be conveniently termed a green-yellow indication repeating relay which is energized whenever its associated si nal displays either a green or a yellow aspect.

The search-light signals Bi, Cl and G shown in Fig. 2 and indicated by symbols on the control panel of Fig. 1A are considered to display green, yellow and red indications, but the remaining signals shown in Fig, 2 and indicated in Fig. 1A are assumed to display yellow and red indications. It is to be understood of course that other aspects or indications may be displayed by changing the color of the roundels, or by some suitable arrangement of the signals in-combination with other signals, but these aspects or indications have been chosen for convenience in disclosing the invention because green is usually considered a high speed indication for proceed; yellow is usually considered a medium or slow speed indication for proceed; and red is considered a danger or stop indication. Although the typical signal illustrated in Fig. 5 is shown as having all three indications, it is to be understood that the green indication may be omitted for those slow speed signals which do not require such indication, and that the only difference in control is that a reversal of the polarity on the winding I82 is not provided. The control of the winding I 82 of the typical circuit of Fig. 5 is shown as provided by a typical signal control relay G, it being understood that each of the signal control relays of Figs. 1A, 1B, 3A and 3B controls its respective signal mechanism.

The track layout for this embodiment of the present invention is divided into track sections 2T and ST in the usual manner by insulated joints, and track circuits (not shown) are provided in the usual manner for the energization of track relays 2TB, and 3TB respectively.

Control machine.A control machine for use in accordance with the present invention has a control panel upon which is constructed a miniature track diagram as illustrated in Fig. 1A to correspond to the track layout for which the system is provided. Disposed on the track diagram at points corresponding to the signal locations, are entrance and exit buttons NB and X13 for the espective entrance and exit points defined by the location of the signals of the track layout. That is, entrance buttons ANB, BNB, CNB, DNB and ENB are provided for the designation of the signal locations A, B, C, D and E respectively as entrance points. The exit buttons AXE, BXB, CXB, DXB and EXB are provided for designation of the signal locations A, B, C, D and E respectively as exit points.

The button ANB for designation of an entrance point for a route governed by dwarf signal A has an operated position when rotated in a counterclockwise direction from its normal position. The buttons DNB and ENB for designation of entrance points for routes governed by dwarf signals D and E respectively have operated positions when rotated in a clockwise direction from their normal positions. The buttons BNB and CNB have, in addition to having operated positions provided by counter-clockwise rotation for selecting low speed signals, depressed operated positions are also provided for the selection of high speed signals for governing the entrance to routes. Each of these buttons can also be pulled out from its normal position to cause restoration to normal of the route establishing means for a route originating at that point. The buttons which may be depressed or pulled are biased to their normal positions, but all buttons which have rotated operated positions remain in such positions until restored. The construction of a control button to provide such operated positions can be provided, for example, as shown in the application of J. F. Merkel, Ser. No. 158,720, filed August 12, 1937. Each of the exit buttons X3 is a push button of the self-restoring type having a contact closed only when such button is depressed.

Although separate entrance and exit buttons are provided in this embodiment of the present invention for each of the route ends, it is to be understood that a single button for each route end can as well be provided having the required number of distinctive positions for designation of the entrance and exit points for that route end, or a single button for each route end can be provided in combination with circuit means for selecting the desired number of operating condilever SML is provided on the control panel for each track switch, such lever being useful in attempting to operate its respective track switch to free it of obstructions.

System deoices.An entrance relay NR (see Figs. 1A and 1B) is provided for each of the entrance points, such relay being responsive to the designation of that entrance point by an operator, and being maintained energized until rcstor ation is effective in a manner which will be here inafter described in detail.

A relay XR is provided for each of the exit points, such relay being energized responsive to the designation of its corresponding exit point where there is an available route extending to that exit point from an entrance point which. has been designated. Each exit relay XR is maintained energized, dependent for deenerg zation upon the restoration of the entrance relay NR for the entrance end of the route having its entrance and exit points designated.

A relay Y is provided for each track switch. such relay being energized in this embodiment of the present invention upon designation of an entrance point, if that track switch can be trailed in a normal position in an available route extending from such entrance point. Such control for each of the relays Y provides that it can be used under certain conditions for the preselection of the normal or reverse position of its track switch in accordance with a route being established.

Normal and reverse switch control relays N and R are provided for each track switch for causin its respective normal and reverse operation in accordance with each route being established. The N or R relay energized for each track switch in the establishment of a route is maintained energized as long as the route locking for that track switch is effective.

With reference to Fig. 2, normally energized directional stick route locking relays ms and 3ES are provided for eastbound traffic, and relays 2WS and 3WS are provided for westbound trailic. Each of the track sections 2T and 3T has a normally energized lock relay L which is controlled in accordance with the route and detector locking, and each of the track switches has a lock stick relay LS which is normally energized, but is dropped away upon the establishment of a route after its track switch has completed its operation to its required position. The use of the route locking relays ES and WS in combination with the lock relays L and LS provides that the track switches can be operated only under safe and desirable conditions.

A polar neutral relay WZ is provided for each of the, track switches for governing its operation in accordance with the normal or reverse control selected by the relays N and R for that track switch, such relay WZ providing features generally required in practice, such as a means for reversing its switch machine in midstroke, and insuring the complete operation of its track switch each time operation has been initiated.

The control of each of the search-light signals is governed by a signal control relay G, which is energized for the signal governing entrance to each route when such route is established.

Having thus considered the apparatus provided in this embodiment of the present invention and its general application, the mode of operation and the principles involved will now be considered under various typical operating conditions which would be encountered in practice.

Operation Normal conditions.The conditions assumed in this disclosure as being normal are the conditions of the system when there are no routes established, or partially established, no track sections occupied within the interlocking plant, and the signals governing traffic through the track layout are all at danger. The track switches 2 and 3 (see Fig. 2) are shown in their normal positions because it is assumed that the last route established through the track layout required that they be in such positions, as the track switches remain in their last operated positions.

Under normal conditions the relays are all deenergized as illustrated with the exception of the track relays TR (see Fig. 2), the switch repeater relays WP, the lock relays L and LS, the route locking relays ES and WS, and the correspondence relay NCR for each track switch. The relays WP and TR are normally energized by circuits well known to those familiar with the art, and the lock relays for each of the track switches are energized by circuits shown in Fig. 2 of the accompanying drawings.

The route locking relay 2E8 is normally energized by a circuit closed from including back contact ill of relay AG, back contact ll of relay BIG, back contact l2 of relay BZG, front contact l3 of relay 2E5, and winding of relay 2E8, to The route locking relay 3ES is normally energized by a circuit closed from including back contact 9 of relay CIG, back contact M of relay (32G, front contact l5 of relay 3ES, and winding of relay 3ES, to The route locking relay 3WS is normally energized by a circuit closed from including back contact N3 of relay EG, back contact I! of relay DG, front contact l8 of relay 3WS, and winding of relay 3WS, to The route locking relay 2WS is normally energized by a circuit closed from including front contact IQ of relay 3WS, front contact 20 of relay ZWS, and winding of relay ZWS, to

The lock relay 2L for track switch 2 is normally energized by a circuit closed from includin front contact 2| of relay 2E8, front contact 22 of relay 2TB, front contact 23 of relay 2W8, winding of relay 2L, and front contact 24 of relay 2L, to The lock relay 3L for track switch 3 is normally energized by a circuit closed from including front contact 25 of relay 3ES, front contact 26 of relay 3TB, front contact 21 of relay 3W8, winding of relay 3L, and front contact 28 of relay 3L, to The lock stick relay 3LS for track switch 3 is normally energized by a circuit closed from including front contact 29 of relay 3L, back contact 30 of relay 3WZ, and winding of relay 3LS, to The relay 2LS provided for track switch 2 is energized normally by circuits (not shown) corresponding to circuits provided for the energization of relay 3LS. The norma1 correspondence relay BNCR for track switch 3 is normally energized by a circuit closed from including back contact 3| of relay 3R, winding of relay 3NCR, polar contact 32 of relay 3WP in a right hand position, and front contact 33 of relay 3WP, to A correspondence relay 2NCR for track switch 2 is energized by a circuit (not shown) corresponding in character to the circuit described for relay 3NCR.

Route establishing circuit mama-Inasmuch as this invention relates to improvements in the entrance-exit system described in detail in the patent to A. Langdon, Patent No. 2,148,865, dated February 28, 1939, and in the prior application of S. N. Wight, Ser. No. 275,923, filed May 26, 1939, reference may be made to those prior disclosures for a more complete description of the route establishing circuit means and its universal application to complex track layouts in which optional routes and other traffic problems ellcountered in practice are involved. However, the general mode of operation of the route establishing means of the system as more directly related to the features of the present invention will be pointed out as the description progresses, and will be in part obvious from specific typical examples to be described.

In the establishment of a route, an operator causes the energization of an entrance relay NR for the entrance end of the route to be established by actuation of the entrance button NB associated therewith. If he desires the route to be governed by a low speed signal, such as a callon or dwarf signal, he rotates the entrance button NB associated therewith in a counterclockwise direction if the signal is for east-bound traffic, and in a'clockwise direction if the signal is for west-bound traffic. This causes the energization of an entrance relay associated with.

such iow speed signal which relay is maintained energized dependent upon the restoration of the associated button from its rotated position. On the other hand, if the route to be established is to be governed by a high speed signal, the designation of the entrance end of such route is effected by the depression of the button NB for the entrance point, such designation being ef fective to cause the energization of a different entrance relay NR for the high speed signal. When an entrance relay NR is picked up for a high eed signal, it is maintained energized until a train enters the track section in advance or until restoration effected by the pulling out of the associated button.

Responsive to the picking up of an entrance relay NR upon designation of an entrance point,

energy is fed through each branch of the initiating circuit network for the direction of traffic designated which corresponds to a route available for use emanating from such entrance point. Energy feeding through such initiating network causes the energization of a route selecting relay Y for each track switch in the track layout that can be included in a predetermined position (generally a normal position) when'trailed'in an available route emanating from the entrance point having its entrance relay NR energized. The feeding of energy through the various branches of the initiating network correspond- A to available routes emanating from each entrance point designated also conditions each of the exit relays for each of the exit points that can be included in an available route extending from the entrance point having its entrance relay NR energized. That is, the picking up of an exit relay XE is dependent upon the designation of that exit point by an operator upon the depression of the exit button XB associated therewith, and is also dependent upon the feeding of energy through the initiating network from the front contacts of an entrance relay NR for the opposite end of an available route extending to that exit point. Inasmuch as the establishment of a route is dependent upon the picking up of an exit relay XR. for the exit end of that route, it is believed to be readily apparent, that a route can be established only when it is available because the circuit selections for the control of the exit relay XR for each exit point provide that such relay can be energized only if thereis an available route extending from a designated entrance point to that exit point.

Upon the energization of an exit relay XR in the establishment of a route, a completion circuit networ: is energized to cause the selective energization of normal and reverse relays N and R for each of the respective track switches to correspond with the route being established, such N and R, relays having their circuits selected in accordance with the condition of the route selecting relays Y included in the initiating circuit 7 network for the particular direction of the route being established.

Establishment of a route.To consider as a specific example how the present embodiment follows such general mode of operation in the establishment of a route, assume that an operator desires to set up a route from C to D governed by the low speed signal 02 (see Fig. 2).

For designation of an entrance point at signal location 0 for th clearing of a low speed signal for the route when it is established, an operator rotates the button CNB in a counterclockwise direction, and thus closes operating contacts on by the low speed signal C2.

the button CNB to cause the picking up of the entrance relay CZNR, (see Fig. 13) by the en'- ergization of 'a circuit closed from including contact 36 of button CNB in a counter clockwise rotated position, back contact 35 of relay CINR, and winding of relay CZNR, to (l.

Upon the picking up of relay CZNR energy is applied to the initiating network for east bound trafiic at front contact 36 to condition the exit relays DXR and EXR. for energization upon designation by an operator of an exit point with which either of those exit relays XR is associated. In accordance with the principles as heretofore set forth, the picking up of relay CENR does not cause the energization of any Y relays as there are no track switches that can be trailed from an entrance point at signal C2.

Upon designation of an exit point for a route by the depression of button DXB, subsequent to the designation of an entrance point at signal C2, the relay DXR is picked up by the energization of a circuit closedfrom (B-), including front contact 36 of relay C2NR, back contact 37 of reley CiNR, back contact 38 of relay CXRA, back contact 39 of relay 3N, winding of relay DXR, back contact it! of relay DNR, and contact M of button DXB, closed in a depressed position, to (ON).

Upon the picking up of relay DXR, a stick circuit is closed for that relay from (13-), including front contact 3% of relay CZNR, back contact 3? of relay ClNR, back contact 38 of relay CXR back contact 39 of relay 3N, winding of relay DXR, front contact 42 of relay DXR, and polar contact In of relay DXR, in a left hand position, to (CN).

In considering the circuits just described for relay DXR it will be noted that the stick circuit for that relay can be closed only if such relay is picked up by energy of a particular polarity applied by the entrance relay CZNR governing enonly when the entrance relay CZNR is picked up,

as the picking up of relay CINR, would apply the opposite polarity upon the closing of front con tact 3! of relay CINR. Such mode of operation is provided because it is assumed that the route over track switch 3 reverse can be governed only Inasmuch as the switch control relays N and R are maintained energized when a route is established until after restoration has been effective (either by manual control or upon passage of a train in a manner to be hereinafter described), the back contact 39 of relay 3N in the circuit for relay DXR checks that there is no route established in which the normal position of the track switch 3 is called for. Thus, the energization of relay DXR indicates that the establishment of a route includ- 2. reverse position can DXR, polar contact'lll of relay DXR in a lefthand position, upper winding of relay SR and back contact 44 of relay 3N, to The pickfing up of relay 3R causes the operation of the trackswitch 3 to a reverse locked position to establish a route from signal C2 .to signal D in a manner which will be hereinafter considered when considering the switch control circuits more in detail.

It may be well to point out in passing that even though the relay DXR may be picked up when energized with the polarity selected by point for signal C2 at a time when a route is available extending from signal C to signal E. The rotation of the button CNB in a counter clockwise direction causes the picking up of relay C2NR in a manner which has been described,

and the'designation of an exit point for a route extending from signal C2 to signal E by the depression of button EXB causes the picking up of the exit relay EXR by the energization of a; circuit closed from (B-), including front contact 36 of relay C2NR, back contact 31 of relay ClNR, back contact 38 of relay CXR back contact 45 of relay 3R, winding of relay EXR, back contact 46 of relay ENR, and contact 41 of buttun EXB closed in a depressed position, to (CN). The picking up of relay EXR closes a stick circuit for that relay at front contact 48 to shunt contacts 46 and 41 out of the circuit just dencribed.

When relay EXR is picked up in the establishment of a route from signal C2 to signal E,

.relay 3N is picked up by the energization of a circuit closed from including front contact 49 of relay EXR, upper winding of relay 3N, and back contact 50 of relay 3R, to The picking up of relay 3N causes the operation of the track switch 3 to a corresponding, normal position in a manner which will be hereinafter described.

If, in the setting up of the route from C to E as described above, an operator desires the clearing of a high speed signal governing entrance to such route, he designates the entrance point thereto by the depression of button CNB instead of its rotation which has been described. Thus, the depression of button CNB, when the normal conditions of the system exist as they have been described, causes the picking up of the entrance relay CINR by the energization of a circuit closed from including front contact of relay 3TH, back contact 52 of relay CZNR, contact 53 of button CNB closed in a depressed position, and winding of relay CINR, to Upon the picking up of that relay a stick circuit is closed to maintain it energized after the button CNB is restored to its normal position from including front contact 5| of relay 3TB, back contact 52 of relay C2NR, contact 53 of button CNB closed both in a depressed and a normal position, front contact 54 of relay CINR, andcwinding of relay CINR, to Thepicking up of relay CINR applies energy to the initiating circuit network in an obvious manner at front contact 31, and renders effective the picking up of exit relay EXR. upon designation of an exit point at E in a manner similar to that which has been described. r I To consider a typical example of the establishment of a route in which a route selecting relay Y is involved, assume at a time when normal conditions of the system exist as they have been described, that an operator desires to establish a route from signal B to signal 0. The designation of an entrance point for such route by the rotation of button BNB in a counter clockwise direction causes the picking up of relay BZNR. for defining an entrance point for the low speed signal B2 by the energization of a circuit similar to the circuit described for the picking up of relay CZNR in accordance with the rotation of the button CNB. Upon the picking up of relay BZNR, the relay 2Y is picked up by the energization of a circuit closed from (13-), through a circuit including front contact 55 of relay BZNR, back contact 56 of relay BINR, back contact 51 of relay BXR, back contact 58 of relay 2R, and winding of relay 2Y, to (CN).

Upon the depression of button CXB for designation of the exit end of the route being established, the exit relay CXR is picked up by the energization of a circuit closed from (13-), including front contact 55 of relay BZNR, back contact 56 of relay BINR, back contact 51 of relay BXR, back contact 58 of relay 2R, front contact 59 of relay 2Y, winding of relay CXR, wire 60, back contact 6| of relay CXR and contact 62 of button CXB closed in a depressed posion, to (CN). The picking up of that relay closes a stick circuit at front contact 63 (see Fig. 1A) to shunt contacts BI and 62 out of the circuit just described.

Upon the picking up of relay CXR in the establishment of a route from signal B2 to signal C, relay 2N is picked up (because it is selected by the picked up position of the relay 2Y) by the energization of a circuit closed from including front contact 64 of relay CXR, front contact 65 of relay ZY, upper winding of relay .2N, and back contact 66 of relay 2R, to

established, he depresses the button BNB, and

the relay BINR responds because of the energization of circuits similar to the circuits described for the energization of relay CINR in accordance with the depression of the button CNB for designation of an entrance point at the high speed signal Cl.

Switch c0ntroZ.-In considering the control of the switch machine SM, the description is more particularly directed to the control of the switch machine 3SM as the control of that switch machine is typical of the control provided for switch machine ZSM, and for additional track switches as required in more complex track layouts encountered in practice.

As a typical example of how a track switch is operated to a reverse position from a normal position when the reverse control relay R for that track switch is picked up, assume when track switch 3 is in a normal position, that an operator causes the picking up of relay 3R as has been described in setting up a route from signal C2 to signal D, The picking up of relay 3R under such conditions causes the picking up of the polar neutral relay 3WZ with its polar contacts operated to a left hand position, and the picking up of that relay causes energy to be applied to the control circuit for the switch machine 38M to cause the operation of the track switch 3 to its reverse locked position. Upon the picking up of the relay SE in the setting up of that route, the normal correspondence relay SNCR is dropped away, and the dropping away of that relay closes a stick circuit for the relay 3L8 which maintains that relay energized until the operation of the track switch 3 has been completed, such stick circuit being opened upon the picldng up of the reverse correspondence relay 3RCR at that time to cause the relay 5L8 to drop away. The dropping away of relay 3LS opens the control circuit for the switch machine 38M and closes a circuit for the energization of a signal control relay in a manner hereinafter described when considering more specifically the signal controls.

To consider more specifically the circuits providing the above described general mode of operation, the picking up of relay 3R causes the dropping away of relay 3NCR by opening the circuit for that relay at back contact 3|. Relay 3W2 is picked up responsive to the picking up of relay ER with its polar contacts operated to a left hand position in accordance with the energization of a circuit closed from including front contact 3| of relay 3H, and lower winding of relay 3W2, to The picking up of relay 3WZ causes energy to be applied to the control circuit for the switch machine 38M to cause its operation to a reverse locked position. The switch control circuit is maintained closed during the operation of the switch machine because relay 3L3 is maintained energized during such time by the energization of a circuit closed from including front contact 29 of relay 3L,

back contact 59 of relay 3RCR, back contact of relay ENCR, front contact H of relay 3L8, and winding of relay 3L8, to After the operation of the track switch has been completed, the

relay ERCR. is picked up by the energization of a circuit closed from including back contact 32 of relay 3N, winding of relay iiRCR, polar contact 32 of relay 3W]? in a left hand position, and front contact 33 of relay 3WP, to The picking up of that relay causes the dropping away of relay 3L5 by opening the stick circuit for that relay at back contact til, the normally energized circuit'heretofore described for that relay being open at back contact 39 of relay 3W2. The dropping away of relay 3LS opens the control circuit for the switch machine 33M in an obvious manner at front contacts 13 and 14 and closes a signal control circuit to be hereinafter described.

To insure the complete operation of the switch machine 38M, once operation has been initiated, a stick circuit is provided for the relay 3WZ which is closed when relay 3WZ is energized for a reverse control from including back con- 3W2, back contact 69 of relay ERCR, back contact ll! of relay SNCR, front contact ll of relay SLS, and winding of relay SLS, to Such circuit provides that relay 3L8 is maintained picked up to close the control circuit for the switch machine 38M during switch machine operation, even if the lock relay 3L should drop 75 away during operation of the switch machine.

To consider how the track switch 3 is operated to a normal position from a reverse position in accordance with the picking up of the normal switch control relay 3N, as is effected, for example, in setting up a route from signal Cl or C2 to signal E, assume that the ends of such a route have been designated by an operator at a time when the track switch 3 is in a reverse position. The picking up of relay 3N under such conditions causes the dropping away of the correspondence relay 3RCR by the opening of the circuit for that relay at back contact 12, and the picking up of that relay also causes the picking up of relay SWZ by the energization of an obvious circuit closed at front contact 12 for its upper winding, such energization causing relay SWZ to be picked up with its polar contacts operated to a right hand position to close the control circuit for switch machine 38M and thus cause the track switch 3 to be operated to a normal locked position. Relay 3L8 is maintained energized during the operation of the switch machine 38M by stick circuit means as heretofore described, and the completion of operation of the switch machine 38M is insured by the energization of a stick circuit for relay 3WZ closed from including back contact 15 of relay 3WP, front contact it of relay 3WZ, polar contact ll of relay 3WZ in a right hand position, and upper Winding of relay 3W2, to After the switch machine has completed its operation, the normal correspondence relay SNCR is picked up by the energization of a circuit which has been described, and the relay 3L8 is dropped away by the opening of the stick circuit for that relay at back contact 10 to open the switch machine control circuit and to close the signal control circuit in a manner to be hereinafter described.

As an auxiliary means of switch control, an auxiliary switch control lever SSML can be actuated to govern the operation of each track switch. For example, the auxiliary switch control lever 3Sl\/H provided for track switch 3, when operated from its center to its upper position, causes the picking up of relay 3R, if the normal conditions of the system exist as they have been described, by the energization of a circuit closed from (-1-), including contact 18 of lever 3SML in an upper position, center winding of relay 3R, and back contact 19 of relay 3N, to The picking up of relay 3R due to such energization causes the operation of the switch machine 33M to a reverse position in accordance with the same mode of operation which has been described when assuming relay SE to be picked up responsive to route control as designated by the actuation of entrance and exit buttons by an operator.

If an operator desires to cause the operation of the track switch 3 to a normal position by auxiliary control, he actuates the lever SSML to a lower normal operating position, and relay 3N responds to such operation because of the energization of a circuit closed from including contact '18 of lever ESML, closed in a lower'operating position, center winding of relay 3N, and back contact 8a) of relay 3R, to The picking up of relay 3N causes the operation of the switch machine 38M to a normal position in accordance with the same mode of operation which has been described when the relay 3N is enerator of entrance and exit points of a route inthe signal C2 to display a low speed signal ascluding the switch 3 in a normal position. pect.

Signal controls-Each of the search-lightv sig- If, on the other hand, the operator had desired nals for the track layout of Fig. 2 is governedin to clear the high speed signal CI, he would have accordance with the energization and deener- 5 depressed the entrance button CNB (instead of gization of a signal control relay G which is enrotating it in a counterclockwise direction) which ergized over a signal control circuit network sewould have resulted in the picking up of the lected by the switch control relays of the route entrance relay CINR in a manner above deestablishing means shown in Figs. 1A and 1B. A scribed. This would place positive potential from single circuit network is provided for this pur- (B+) on the initiating network so that the acpose. to effect the energization of the relays G tuation of the exit button EXB would cause the for signals governing trafilc in both directions, exit relay EXR to be picked up and close its stick and the relay G for any particular signal can circuit. The relay EXR then energizes the combe energized only after the route which it is to pletion network, as above described, to establish govern has been completely established and the the route. track switches included therein have become When the route is properly established, and locked. providing the track section 3T is unoccupied, the It has been explained above how a. route may signal control relay CIG is energized by a circuit be established from signal location C to signal closed from including front contact 9| of location D by the rotation of the entrance button relay EXR, front contact 92 of relay 3NCR, back CNB and the momentary actuation of the exit contact 83 of relay 3RCR, back contact 84 of button DXB. After the track switch 3 has oprelay 3LS, back contact 85 of relay CXR front erated to a reverse locked .position into correcontact 88 of track relay 3TB, front contact 89 spondence with its control by the relay 3R, the of entrance relay CINR, windings of relay CIG, relay 3LS is deenergized (see Fig. 2) as above deto scribed. This closes the signal control circuit The signal mechanism of signal C I is controlled network. so that the signal.v control relay C2G is not only by its signal control relay CIG but its energized from over a circuit including polar energizing circuit is also energized with one pocontact I12 of relay DXR. in a left-handposilarity or the other in accordance with the clear tion, front. contact 8I of relay DXR, back conor stop indication of the next signal in advance tact 82 of relay 3NCR,.front. contact 83 of relay governing trafiic in the same direction. In other IIRCR, back contact 84 of relay 3LS, back contact words, the signal G, when at stop, causes its 85 of relay CXR front contact 86. of relay CZNR, associated green-yellow indication relay GGYP winding of relay CZG, to to be deenergized, but when displaying a yellow This energization of the relay CZG closes front or a green proceed indication, such relay is encontacts I85 and I86 to energize its associated ergized, which in turn governs signal 0 c r signal mechanism G2 with such a polarity as to ingly.

cause that signal to actuate its yellow roundel Y If the signal G is at stop, then the picking up to an active position and display a slow speed of the signal control relay C'IG causes positive orcall-on signal aspect. ipotential to be applied to the signal mechanism t may be noted that any accid ntal manipuof signal CI from through a circuit includlation 1 e P Of the operator which might ing back contact I81 of relay GGYP, back conresult in the p c g p O the relay CINR tact I89 of relay 3RCR, front contact I90 of response to the depression of the button CNBfi relay CllG, signal mechanism for signal CI, front fOllOWGd by the actuation of the exit button DB "5 ontact l9l of re1a,y CIG, front ontact [92 of d. n p s y cause th le rin of the s erelay 3RCR', back contact I94 of relay GGYP, nal CI, instead of the signal C2. In the first to Thus, the signal CI is energized with p as pointed Out above he actuation of the such a polarity that its movable member actuates P r contacts of the relay DXR t0 E the yellow roundel Y into an active position to Positions fails to 0105B @0131 o t in a 59 cause such signal to display a caution signal asleft-hand position SO that the. route would IlOt peat namely approach the next, signal prepared be established. In the second place, the polar t stop contact I12 would be in a td position a If, on the other hand, the signal G is cleared, so that e S n Control relay CIG could not then the relay GGYP is energized and contacts rec ive n r y v n thouehthe front Contact 89 I81 and tea causes the polarity of energization of the entran e r y CINE might be closedof the signal mechanism for signal CI to be re- In Setting p a mute O C o the Operator versed to thereby cause the green roundel G to ay cause either t high p d s l CI r Y be moved to an active position so that the sigthe low speed signal C2 to be cleared at his disnal C l displays a high speed proceed aspect. It

cretion and dependent upon e characteristic p- 60, should be understood that signal G may be aneration of the entrance button CNB. other manually controlled signal of another in- If, for example, the operator rotates the enterlocked group, or may be a signal governing trance button CNB in a counterclockwise direction automatic signal territory,

followed by the actuation of the exit button EXB Thus, it is evident that the system of the presto effect the response of the route establishing 5 ent invention requires manipulations on the part means as above described, a circuit is closedfor of the operator to not only designate the enthe relay CZG from through a circuit intrance and exit ends of the desired route but to eluding front contact 9| of relay EXR, front also designate the entrance end in a manner contact 92 of relay 3CNR, back contact 83 of characteristic of the class of signal which is to relay 3RCR, back contact of relay LS, back govern that route. If a route is to allow only contact 92 of relay CNCR, back contact 83 of slow speed traffic, then the signal at the entrance ,relay C2NR, windings of relay 02G, to to that route can be cleared only when the oper- The picking up of the relay CZG closes front ator designates that signal location as an encontacts- I85 and I86 to so energize its associated trance point in a manner characteristic of a slow signal mechanism G2 with a polarity to cause speed signal. If. some route may have eitherhigh speed or slow speed trafiic, then the operator may optionally determine whether a slow speed or a high speed signal indication shall be given by the manner in which he actuates the entrance button with the limitation that the high speed signal shall be controlled in accordance with traiiic conditions so as to give its high speed indication only providing the neXt signal in advance is clear and trafiic is such that the train can proceed in accordance with such high speed signal aspect.

It is believed from the typical examples which have been described that it will be readily apparent how the signal control circuit network is organized to provide control for each of the signal control relays G, and how such organization can be modified to fit any particular track layout encountered in practice.

Route locking.The use of the entrance-exit system provided by the present invention in the governing of complex track layouts requires the use of route locking which can be provided in accordance with the requirements of practice. One form of route locking which seems to be preferred in many cases for use with entrance-exit types of systems is that in which normally energized directional stick relays are provided for the track section and are governed by an arrangement of circuits which provides that the route locking relays for the particular direction for which a route is established are dropped away for the track sections included in the established route in advance of a train, and such relays are again picked up as the train progresses through the route upon the energization of the respective track relays for the track sections in the rear of such train. Such an organization provides what is generally known in practice as sectional release route locking.

Although the simple track layout used for this embodiment of the present invention does not require the full quota of directional stick route locking relays that would be required for each track circuit in a complex track layout, a direc tional stick relay ES and a directional stick relay WS for respective east and west bound traffic is provided for each track section as a typical example of how such route locking relays would be provided in more complex track layouts. Thus, the route locking relays ZES and 3E8 (see Fig. 2) are provided for respective track sections 2T and 3T for east bound traific, and the directional stick relays 2W8 and 3W8 are provided for the respective track sections 21 and 3T for west bound trafiic.

Upon the establishment of a route from signal location to signal location D, as has been described, the picking up of signal control relay CZG causes the dropping away of the route locking relay 3E8 by opening the circuit for that relay at back contact M, and the dropping away of relay 3E8 causes the dropping away of the lock relay 3L for track switch 3 by opening the circuit for that relay at front contact 25. The dropping away of relay 3L, under such conditions, causes the establishment of a stick circuit for relay 3R (which is picked up at that time) closed from including back contact 93 of relay 3L, front contact as of relay 3R, center winding of relay 3R, and back contact 79 of relay 3N, to Such stick circuit is closed to maintain relay 3R picked up as long as the track switch 3 is locked by the route locking in order to prevent the so-called preconditioning of routes. That is, with reference to Fig, 1B the picked up position of relay 3R by opening backcontact 45 prevents the picke ing up of the exit relay EXR if' an operatoriattempts to establish a conflicting route which requires the track switch 3 to be in a normal position by the opening of back contact 4*5. It is also of course provided that the dropping away of the lock relay 3L prevents the application of energy to the control circuit for the switch machineBSM by opening the circuit for the lock relay 3LS at front contact 29. In. more complex track layouts where more than one track switch is included in the route, the dropping away of the route locking relay ES or WS for'the track switch nearest the signal governing entrance to such route causes the route locking relays for that direction of traflic to be successively deenergi'zed for. the other track switches included in the route. For a more detailed description of how such general mode of operation is provided, reference can be -.made to the patent toA. Langdon, Patent No. 2,148,865, dated February 28, 1939, and if approach locking is to be provided as well, the circuits for the directional stick relays can be pro-- vided, for example, as shown in the patent to ,C. F. Stoltz, Patent No. 2,115,511, dated April 26,

After a train has left the track section for which a route locking relay is deenergized, such route locking relay is picked up. For example,

3 0 13118 passage of a train through the route from signal C2 to signal D allows the picking up of relay 3E8 responsive to the picking up of the track relay 3TB in. accordance with the generalrestoration procedure as hereinafter described.

Restoration to normalr-The restoration to normal of parts of the system associated with the establishment of each route, and the restoration to stop of the signal governing entrance to such route can be efiected either by' the manual actu to; ation of the entrance button NB for entrance to such route, or, in the case of stick signals and semi-automatic high speed signals, upon the entrance of a train into the route established.

To consider how manual restoration to normal is effected, assume, for example, that an operator has caused the establishment of a route from signal C to signal E, such route being governed by the low speed signal C2. To cause that signal to be restored to stop, and the parts of the system associated with the establishment of that route to be restored to normal, with the route unoccupied by a train, an operator rotates the entrance button CNB (see Fig. 1A) in a clockwise direction back to its normal position. Such rotation causes the dropping away of relay CZNR (see Fig. 1B) by opening the circuit for that relay at contact 34 of button CNB, and the dropping away of that relay causes the signal control relay 02G which governs the low speed signal C2 to be dropped away by opening the circuit for that relay at front contact 86. The deenergization of the search light signal C2 causes such signal to display a red stop indication.

The dropping away of relay. CZG causes the picking up of the lock relay 3E8 (see Fig. 2) by the energization of a circuit closed from including back contact 9 of relay Cl G, back contact 14 of relay 02G, front contact of relay 3TB, and winding of relay 3E8, to When relay 3ES is picked up, a stick circuit which has been described ,is established for that relay ,to maintain it energized upon passage of a west bound train through track section ST. The relay BL is picked up upon the energization of relay SES by the energization of a circuit closed from (-1-), including front contact 25 of relay 3ES, front contact 26 of relay 3TB, front contact 21 of relay 3W8, winding of relay 3L, and contact 91 of lever 3SML closed when such lever is in its center position, to When relay 3L is picked up, a stick circuit is established for that relay as has been heretofore described.

The dropping away of relay CZNR, responsive to restoration designation by an operator, causes the dropping away of the exit relay EXR for the route established by the opening of the circuit for that relay at front contact 36 (see Fig. 1B), and such relay in dropping away efiects the release of relay 3N by opening the pick-up circuit for that relay at front contact 49. The stick circuit for the center winding of relay 3N is opened upon the picking up of relay 3L (see Fig. 2) at back contact 93. The dropping away of relay 3N causes the dropping away of the polar neutral switch control relay 3WZ by opening the circuit for that relay at front contact 12. When relay 3WZ is dropped away, a circuit is closed to cause the picking up of the lock relay 3LS from including front contact 29 of relay 3L, back contact 39 of relay 3WZ, and winding of relay 3LS, to thus completing restoration to normal of the parts of the system associated with the setting up of a route from signal C2 to signal E.

If an operator wishes to cause the restoration to normal of the signal Cl when it governs an established route from C to E, such restoration is efiected in a manner similar to that described except that it is initiated by the pulling out of button CNB to open contact 53 in the stick circuit for relay CINR, which in turn efiects the restoration of the system by opening front contacts 31 and 89.

To consider a typical example of how automatic restoration can be effective for a route upon passage of a train, assume that the signal Cl is cleared for a route established as has been described from signal C to signal E, and assume an approaching train to accept signal Cl and enter track section 3T. The dropping away of relay 3TRpcauses the dropping away of the entrance relay C INR by opening the circuit for that relay at front contact 5| (see Fig. 1B), and the dropping away of relay CINR. under such conditions causes the restoration to normal of parts of the system associated with the established route from signal CI to signal E in a manner similar to that which has been described except that the restoration of the route locking is effective only after the passing train has left track section 3T, and thus the relay 3L (see Fig. 2) can only be picked up after the train has left that route. Inasmuch as the restoration of the relay 3N is dependent upon the release of the stick circuit for that relay upon the picking up of relay 3L, the restoration to normal of the relays 3N, 3WZ and 3LS does notbecome effective until relay 3L has been picked up after the restoration of the route looking for that route.

Through route control.-Alth0ugh it is proposed in accordance with the present invention to provide an entrance-exit type of interlocking system which includes the facility of through route control, it is proposed that such through route control shall be limited to routes which provide for high speed train movements and that manipulations for such through route control shall be characteristic of suchhigh speed signals. This is because of the different kinds of train movements which are made with the different governing signals.

More specifically, low speed signals, such as dwarf and call-on signals, are used mostly for switching purposes to connect one train with another, to run a train into a dead end siding, to run a second train into a station platform or a track section which is already occupied by a first train, and such other low speed train movements which require that the switches of a route be in proper positions and locked but in which it is unnecessary for automatic track circuit control to be included for the'rear end protection of trains. Any low speed signal of this type can of course be cleared only when the route which it governs is completely established and no signal for the opposing direction is also cleared. Thus, the clearing of a low speed signal, such as a dwarf or a call-on, conveys to a trainman an indication that the route in advance is established, but that he must be prepared to stop on sight of a train or other obstruction in advance.

It is therefore very desirable that the clearing of a low speed signal by an operator should be efiected with great care and with the understanding that responsibility for safe train movement has been shifted from the automatic signalling system to the train crew and the operator. Such being the case, it is desirable that a distinctive operation be required for each low speed signal which is to be cleared, and that under no circumstance should a low speed signal be cleared by through route control.

t is proposed in accordance with the present invention to provide an entrance-exit type of interlocking system to accomplish the above mentioned object and at the same time organize the system so that an intermediate high speed signal cannot inadvertently be cleared when the operator has designated the entrance point as governed by a low speed signal. In other words, a signal location may be designated as an entrance point to be governed by a low speed si nal but the operator instead of designating an exit point within the same interlocked group might inadvertently designate an exit point in some succeeding interlocked group which would be the exit end of some through route originating at the designated entrance point. Under such circumstances, certain prior entrance-exit interlocking systems would effect the clearing of the low speed signal for the entrance point designated and also the clearing of the signals for the various intermediate signal locations in the through route. However, the present invention is organized to prevent such operation in response to such manipulation and the high speed intermediate signals may be cleared in response to through route manipulations only providing the entrance point has been designated in a manner characteristic of a high speed signal.

This is accomplished in the embodiment of the present invention by so controlling the through route connections which inter-relate the initiating circuit networks for adjacent interlocked groups, that these inter-connections are closed for available through routes only under circumstances where it is desired that a high speed through route be established.

More specifically, if an operator designates an entrance point for the clearing of a high speed signal by the depression of the entrance button NB for that entrance signal location, a particular polarity is applied to the initiating circuits for the routes originating at that point, which energy causes the energization of a polar neutral relay NP for each signal which may become an intermediate signal in an available through route originating at the designated entrance point. The energization of such entrance repeating relay N'P for a signal location closes the through route connection at that signal location and energizes the initiating circuits of the next interlocked group for the routes originating at such intermediate signal location. Thus, the initiating circuits for each of the interlocked groups forming a part of the through routes originating at the designated entrance point are properly conditioned to effect the preselection of the positions of the switches in such through routes in readiness for the designation of the exit point of a particular one of such available through routes.

However, if an operator designates an entrance point by the rotation of the entrance button for that particular signal location to control a low speed signal thereat, the opposite polarity is applied to the initiating circuits for the routes originating at that signal location which causes the polar neutral relays NP for the signal locations at the ends of the routes within that interlocked group to be so energized that the through route connections are opened, and the only exit relays which are conditioned to be responsive to exit designation are those within the same interlocked group in which the entrance point has been designated.

As an example of such general mode of operation, the designation of an entrance point for the clearing of the high speed signal Bl (see Fig. 1A) causes the energization of the entrance relay BiNR, which, in picking up, applies (B+) energy to the initiating network for the energization of the relay ZY. Upon the picking up of relay BY, the polar neutral relay NP is picked up with its polar contacts operated to a right hand position, and such energization causes a through route connection to be established between the initiating networks for the two adjacent track portions for east bound trafic. Thus, energy feeds through both initiating networks from the source as applied at front contact 55 of the entrance relay BINR, and so conditions the relays for each of the exit points that the designation of an exit point by the depression of either of buttons CXB or EXB causes the establishment of a route extending to that exit point. It is thus provided, by the application of that particular polarity to the initiating networks, that a through route can be set up from signal B! to the exit point at E, when such exit point is designated by an operator upon depression of exit button EXB. However, if the designation of an entrance point for a route governed by the low speed signal B2 is effected by the rotation of the button BNB, the opposite polarity is applied to the initiating network, and energy feeds through such network to cause the picking up of the relay 2Y and the conditioning of the relay CXR for energization, but the polar neutral relay CNP is picked up with its polar contacts operated to a left hand position to maintain open the through route connection between the adjacent track portions at the intermediate signal location, and thus render the designation of either of exit points D or E upon the depression of the button XB for such point ineffective for causing the establishment of a through route.

"To more specifically'point' out how such' mode of operation is eifective, assume, as a typical example, that an operator desires to establish by'end-to endcontrol a through route extending from the high speed signal Bi to, an exit point at signal E. To designate signal location B as the entrance point for such route, the operator depresses the button BNB to close the pick-up circuit of relay BINR from including front contact 205 of relay ZTR, back contact 206 of relay' BZNR, actuated contact 281 of button BNB, windings of relay BINR, to The picking up of the relay BINR closes front contact 203 which shunts out the actuated button contact 20'! of button BNB so as to render the relay BiNR dependent for energization upon front contact 205 of relay ZTR and upon the normally closed contact 207 which may be opened by pulling out the button BNB. The picking up of that relay BiNR causes thepicking up of relay ZY 'in accordance with (B+) energy applied at front contact 56, and the picking up of relay 2Y closes a circuit for the energization of the polar neutral relayCNP from (B+), including front contact 56 of relay BINR, back contact 51 of 'relay BXR, back contact 58 of relay 2R, front contact 59 of relay 2Y, and winding of relay CNP, to (CN). When relay CNP is picked up due to such energization its polar contacts are operated to a right hand position and a through route connection is closed to condition each of the relays DXR and EXR (see Fig. 1B) for energization upon the designation by an operator of the exit point with which such relay is associated.

Thus, if an operator depresses the exit button EXB for designation of an exit point in the establishment of a through route by end-to-end control, the relay EXR (see Fig. 1B) is picked up by the energization of a circuit closed from (B+) including front contact 56 of relay BINR (see Fig. 1A) back contact 51 of relay 3%, back contact 58 of relay 2R, front contact 59 of relay 2Y, front contact 98 of relay CNP, polar contact 99 of relay GNP in a right hand position, back contact lliil of relay CXRQwire IUI, back contact 36 of relay CZNR, back contact 3'! of relay CINR, back contact 38 of relay CXR back contact 45 of relay 3R, winding of relay EXR, back contact 46 of relay ENR, and contact 41 of button EXB closed in a depressed position, to ON. The picking up of relay EXR closes a stick circuit for that relay at front contact 48 to shunt contacts 45 and 47 out of the circuit just described.

Assuming the relay EXR to have been picked up in the establishment of a route by end-to-end control from signal Bl to signal G, the relay 3N is picked up by the energization of a circuit which has been described, and the picking up of that relaycauses the picking up of the through route relay CXP by the energization of a circuit closed from including front contact 49 of relay EXR, front contact I02 of relay 3N, winding of relay CXP, back contact I03 of relay CZNR, and back contact I04 of relay CINR, to The picking'up of that relay closes a stick circuit for shunting contacts I03 and H34 out of the circuit just described, from including front contact 49 of relay EXR, front contact I02 of relay 3N, winding of relay CXP, front contact I of relay CD6, Wire H16, and'back contact I01 of relay CXR, to

When relay CXP is picked up, in setting up a route by end-to-end control, a circuit is closed to j cause the picking up of relay CINR' from ineluding front contact 5| of relay 3TB (see Fig. 13), back contact 52 of relay CZNR, contact 53 of button CNB in a normal position, front contact I08 of relay CXP, and winding of relay CINR, to When relay CINR is picked up, a circuit is closed to cause the picking up of the exit relay CXR for the route extending through the adjacent track portion by the energization of a circuit closed from (3+), including front contact 56 of relay BINR (see Fig. 1A), back contact 51 of relay BXR, back contact 58 of relay 2R, front contact 59 of relay ZY, winding of relay CXR, wire 60, back contact 6| of relay CXR front contact I09 of relay CXP, and front contact IIB of relay CINR, to ON. The picking up of relay CXR causes the dropping away of relay CXP by opening the stick circuit for that relay at back contact IIJ'I, the pick-up circuit for relay CXP having been opened upon the picking up of relay C INR. That relay is made slow enough in dropping away to allow time for the establishment of a stick circuit for relay CXR, which is closed at front contact 63 to shunt contacts 6|, I09 and I I0 out of the pick-up circuit for that relay.

Responsive to the picking up of relay CXR, the

relay 2N is picked up by the energization of a circuit which has been described, and the picking up of that relay completes the selection of the through route extending from signal BI to the exit point at signal E. After the track switch included in the route extending through each of the track portions has been properly positioned in accordance with the energization of the relay N for that track switch, the lock relay LS for that track switch is dropped away to cause the energization of th signal control relay for the signal governing entrance to such track portion in accordance with circuits heretofore described in considering in detail the signal controls provided.

More specifically, the dropping away of the lock stick relay 3LS after the track switch 3 has properly assumed its normal position, causes the energization of the signal control relay CIG which in turn causes the energization of the signal mechanism Cl. is energized with one polarity or the other depending upon whether the signal G is clear or stop so that the signal CI indicates yellow or green respectively depending upon such conditions. As noted above, the signal G may be the entering signal of another interlocked group and manually controlled by means provided in accordance with the present invention, or, as assumed for purposes of this disclosure, such signal G may be the entering signal of automatic block signalling territory and automatically controlled in accordance with traiiic conditions in advance.

Also, the dropping away of the lock stick relay 2LS after the track switch 2 has properly operated to a normal position, effects the energization of the signal control relay BIG by a circuit closed from including front contact I 31 of relay CXR, contact I35 of relay ZLS, back contact I34 of relay 2RCR, front contact I33 of relay ZNCR, back contact I32 of relay BXR, front contact I95 of relay ZTR, front contact I95 of relay BINR, windings of relay BIG, to The energization of the signal control relay BIG closes front contacts I91 and I98 so that the signal mechanism of signal BI is energized with one polarity or the other depending upon whether the contacts I99 and 20 of relay CIGYP ar dropped away or picked up. If the relay C I GYP is dropped away the signal mechanism BI. is energized with such a polarity as to move its yellow roundel Y The signal mechanism CI into an active position causing the signal BI to give a medium speed aspect. On the other hand, if the relay CIGYP is energized, the opposite polarity is supplied to the signal mechanism BI so display either of caution aspect or a high speed aspect, as above described, the relay CIGYP is energized so that the signal BI is caused to give a high speed aspect.

Upon the picking up of relay CXR, in the establishment of the through route just described, the through route connection between the initiating networks for the adjacent track portions is opened at back contact I09, and the initiating network for the track portion having signal CI as an entrance point is energized in accordance with the picked up position of relay CINR at front contact 31 with the proper polarity used in connection with the clearing of high speed signals. In order that the initiating circuit will not be deenergized upon the shifting of contact 31 of relay CINR, front contact I II of relay CXP shunts around contacts 36 and 31 of relay C2NR. and CINR to maintain the through route connection closed while either of such contacts is being shifted in the setting up of a route by endto-end control. When the through route connections are opened at each of the intermediate signals in the establishment of a route by endto-end control, it is believed apparent that the route establishing means for each of the interlocked groups is then in the same condition as would be effected if the route included in each of such interlocked groups forming a. part of the whole through route had been set up in accordance with the designation by an operator of the respective entrance and exit ends of its own interlocked group. Such being the case, it should be apparent that the manual and automatic restoration to normal of the route establishing means is effected in the same manner for each interlocked group, as has been described, the restoration for each interlocked group being independent of the restoration for the adjacent interlocked group.

Single intermediate signal.-With reference to the track layout of Fig. 2, it will be seen that the signal location C provides signals for governing only east-bound trafiic and that westbound trafiic is governed through the track layout by signals D and E. It will thus be readily understood that the route establishing means for the two interlocked groups must be so interrelated that no route can be established from E to B if a route is established from B to C; also, that any route established from E to B should not be interrupted by any manipulation of the buttons CNB or CXB. To accomplish this, a special interlock is provided between the initiating circuits for opposite directions at this intermediate signal location C by the provsion of what might conveniently be termed a phantom exit relay. In other words, a relay CXR, is provided at the signal location C which is picked up when an entrance point is designated at either E or D without requiring an exit designation for the signal location C, and this relay simulates an exit condition at this signal location against which the initiating circuits for the opposite di rection can be interlocked. This relay CXR (see Fig. 1B) has its pick-up circuit controlled so as to check the deenergized condition of the entrance and exit relays at that intermediate signal location and includes certain of its own contacts in the initiating circuit for the opposite direction as well as the pick-up circuit for the exit relay CXR so as to prevent any routefrom being established in such opposite direction.

More specifically, in the setting up of a route for west bound trail-1c from signal E to an exit -point at signal B, the energization of the entrance relay ENR responsive to entrance designation for the route to be established causes the picking up of relay 3Y by the energization of a circuit closed from including front contact H2 of relay ENR', back contact H3 of relay EXR, back contact H4 of relay 3R, and winding of relay 3Y, to and the picking up of that relay causes the picking up of relay CXR by the energization of a circuit closed from including front contact H2 of relay ENR (see Fig, 1B), back contact H3 of relay EXR, back contact H4 of relay 3R, front contact H5 to relay 3Y, winding of relay CXR back contact H6 of relay CINR, back contact II! of relay C2NR, wire H8, and back contact H9 of relay CXR, t The picking up of relay CXR closes a stick circuit at front contact I20 to shunt contacts H6, H1 and H9 out of the circuit just described.

When relay CXR is picked up, a circuit is closed to condition each of the exit relays AXR and BXR. so that it may be picked up upon designation of the exit point with which that relay is associated, if there is an available route extending from the entrance point which has been designated.

Upon depression of the button BXB for designation of an exit point, relay BXR. is picked up by the energization of a circuit closed from including front contact H2 of relay ENR (see Fig. 1B), back contact H3 of relay EXR, back contact H4 of relay 3R, front contact I I of relay 3Y, front contact I 2| of relay CXR), wire I22, back contact I23 of relay 2H,, winding of relay BXR, back contact I24 of relay BINR, back contact I25 of relay BZNR, and contact I26 of button BXB closed in a depressed position, to The picking up of relay BXR, closes a stick circuit for that relay at front contact I21 to shunt contacts I24, I25 and I26 out of the circuit just described.

The response of relay BXR causes the picking up of the relay 2N by the energization of a circuit closed from including front contact I28 of relay BXR, lower winding of relay 2N, and back contact 63 of relay 2R, to Upon the picking up of relay 2N a circuit is closed I38, front contact 85 of relay CXR back contact 84 of relay 3L8, back contact 83 of relay 3RCR, front contact 92 of relay SNCR, back contact 9| of relay EXR, front contact I39 of relay ENR', and winding of relay EG, to The picking up of relay EG causes energy of the proper polarity to be applied to the search light signal E for causing that signal to give a yellow or slow speed indication.

With the route established from E to B and the signal E cleared, it is noted that the relay CXR is maintained energized dependent upon the entrance relay ENR, and when picked up opens contacts 38 and GI as well as back contact 85. The opening of back contact 38 prevents the entrance relays CINR and CZNR from applying potential to the initiating circuit for the opposite direction. In this connection, it is noted that there is no interlocking contacts to prevent the relays CINR or C2NR from being energized at any tim that their respective control button contacts are closed. However, should the relay CINR, for example, be picked up opening back contact I I6, such inadvertent energization of this relay while the route from E to B is established does not deenergize the relay CXR because the stick contact I20 shunts out the interlocking contact I I6. Also, the openin of back contact 85 prevents energy in the signal control network from being passed to either the relays CIG or CZG. The open condition of back contact 6| obviously prevents the picking up of the relay CXR.

In view of the fact that the initiating network control for this route from E to B is entirely dependent upon the picked up condition of the relay ENR, it will be entirely obvious that the restoration of the entrance button ENB to it normal position will restore the signal E to stop and allow the route establishing means to assume a normal condition.

It will be noted that the initiating network of the route establishing means for setting up routes and clearing signals for west-bound trafific is not polarized. This is due to the fact that the track layout chosen for the embodiment of the present invention only has the low speed signals D and E governing west-bound traific and there are no intermediate signals for through route control involved in such west-bound traffic movements.

Thus, it has been unnecessary to make the relays AXR and BXB, of the polar neutral type as shown for the relay DXR. However, it is to be understood that the principles of the invention shown for governing east-bound traflic may also be applied to the means employed for governing west-bound traflic, which would probably be required in an installation of any appreciable size to cause the picking up of relay 3N in accordance with the picked up position of the relay 3Y, from including front contact I28 of relay BXR, front contact I29 of relay 2N, wire I30, front contact I3I of relay 3Y, lower winding of relay 3N, and back contact 50 of relay 3R, to

After the track switches have responded in and complexity of track layout where many double intermediate signal locations would be found requiring both initiating networks to be similarly controlled.

Route establishing circuit means adapted to foreign practice.-As mentioned above. the prinrelay 2LS, back contact l3'l of relay CXR, wire 7 ciples of the present invention may be applied to means which is readily adaptable to provide signalling in accordance with the practices of various foreign railroads. To accomplish a disclosure of such adaptation, the route establishing means of Figs. 1A and 13 have been modified as shown in Figs. 3A and 3B with the corresponding relays and contacts being identified by the same reference characters. It is also to be understood that the route establishing means of Figs. 3A and 3B is to be used with the track layout and typical circuits shown in Fig. 2, the only difference being that the high speed signal CI is eliminated entirely and only a shunt signal is considered to be located at this intermediate signal location. This has been indicated on the control panel by showing the low speed signal symbol C, and such low speed shunt signal is considered to be at the corresponding point of the track layout in Fig. 2. Also, the route locking shown in Fig. 2 is required to be modified as shown in Fig. 4 for reasons hereinafter pointed out in detail. Other differences will be pointed out as the description of this modified form of the invention progresses.

With reference to Fig. 3A, in accordance with foreign practice, the signals A, B2, C, D, E and F are low speed or shuntingsignals used primarily for switching movements, and the signals BI and G are running or high speed signals which can be cleared only when there is an available route extending to the next running signal. That is, if an operator wishes to set up a route for a train from signal BI to signal E, for example, the actuation of the respective entrance and exit control buttons for the ends of that route cause its establishment, and, in accordance with foreign signal practice, a train accepting the entering running signal BI proceeds past the shunt signal C which remains at stop.

If, however, an operator wishes to set up a route from signal B2 to signal E by the clearing of shunt signals for governing passage through such route, he cannot cause such route to be established by the actuation of the respectiv entrance and exit buttons BNB and EXB only, but he must actuate the entrance and exit buttons for each of the respective track portions or interlocked groups involved in the route. That is, a route governed by a shunt signal cannot be established by end-to-end or through route control.

To consider the establishment of a route for clearing a running signal, assume that an operator designates an entrance point for the route from signal B to signal E (see Fig. 3A) by the depression of the button BNB. This closes a pick-up circuit for the relay BINR from (4-), in- L cluding front contact 205 of relay ZTR, back contact 206 of relay B2NR, actuated contact 201 of button BNB, windings of relay BINR, to As soon as the relay BINR, picks up, it closes front contact 208 to shunt out the actuated button contact 201 so that the relay BINR is then maintained energized dependent upon front contact 205 of the track relay 2R although the operator releases the button BNB. It is understood that the operator may release the relay by pulling the button BNB to open the normally closed con tact 201. The picking up of relay BINR causes the picking up respectively of the relays 2Y and CNP by the energization of circuits corresponding to circuits which have been described. The

picking up of relay CNP conditions the relay Em (see Fig. 3B) for energization when the exit point with which such relay is associated is designated. Thus, the depression of the button EXB for designation of the exit point at signal E causes the:

picking up of relay EXR by the energization of a circuit closed from (B+) including front contact 56 of relay BINR (see Fig. 3A), back contact 5'! of relay BXR, back contact 58 of relay 2R, front contact 59 of relay 2Y, front contact 98 of relay CNP, polar contact 99 of relay CNE in a right hand position, wire IOI, back contact 35 of relay CNR, back contact 38 of relay CXR back contact 45 of relay 3R, winding of relay EXR, back con-- tact 46 of relay ENR, and contact 41 of button EXB closed in a depressed position to (ON). The

front contact 48 to shunt contacts 46 and 41 out of the circuit just described.

Responsive to the picking up of relay EXR, the relay 3N is picked up by the energization of a circuit which has been described, and the picking up of that relay causes the picking up of relay CXP by closing a circuit for that relay from including front contact 49 of relay EXR, (see Fig. 3B), front contact I03 of relay 3N, winding of relay CXP, back contact 140 of relay CNR, wire I4I, front contact I42 of relay CNP, and polar contact I43 of relay GNP in a right hand position, to The picking up of that relay closes a stick circuit at front contact I05 to shunt contacts I40, I42 and I43 out of the circuit just described. It will be noted upon considering the stick circuit for relay CXP that such relay is maintained energized, dependent for deenergization upon the dropping away of the exit relay EXR, as compared to the stick circuit for the relay CXP as shown in Fig. 1B which provides that such relay is dropped away as soon as the through route is established.

When relay CXP is picked up, the relay 2N is picked up, because that relay is selected in preference to relay 2R by the picked up position of the relay ZY, upon the energization of. a circuit closed from including front contact I44 of relay CXP, wire I45, front contact of relay 2Y, upper winding of relay 2N, and back contact 66 of relay 2R, to

After the track switches have properly responded to correspond with the picked up position of the relays 2N and 3N, the relays ZLS and 3L5 are dropped away, and a signal control circuit is established to cause the picking up of relay BIG, from including front contact 9| of relay EXR (see Fig. 3B), front contact 92 of relay 3NCR, back contact 83 of relay 3RCR, back contact 84 of relay 3L5, front contact of relay 3TB, back contact I46 of relay CXR front contact I41 of relay CXP, wire I48, back contact I49 of relay CXR, front contact I50 of relay 2TB, back contact I5I of relay 2LS, back contact I52 of relay 2RCR, front contact I53 of relay 2NCR, back contact I54 of relay BXR, front contact I55 of relay BINR, and winding of relay BIG, to

The picking up of the relay BIG closes contacts 20I and 202 so as to cause the signal mechanism BI to be energized, and the polarity of such energization is determined in accordance with whether the next running signal in advance,

relay GGYP closes back contacts 203 and 204 so as to supply energy to the signal mechanism BI of such a polarity as to actuate its yellow roundel 'Y to an active position and cause the signal BI to give a caution signal aspect, that is, approach the next running signal prepared to stop. On the other hand, if the signal G is clear and the relay GGYP is picked up to close front contacts 203 and 204, then the signal BI is energized with such polarity as to actuate its green roundel G to an active position causing such signal to display a high speed proceed signal aspect.

As above mentioned, the directional stick relay 3ES of Fig. 2 has substituted therefor the directional stick relay 3ES in this form of the present invention. This relay 3ES is normally energized by a circuit closed from including front contact I62 of relay 2E3, back contact 

